Oxygen, static-bomb calorimeters

The calorific value is the heat produced by the combustion of a unit quantity of coal in a bomb calorimeter with oxygen and under a specified set of conditions (ASTM D-121 ASTM D-2015 ASTM D-3286 ISO 1928). For the analysis of coal, the calorific value is determined in a bomb calorimeter either by a static (isothermal) method or by an adiabatic method, with a correction made if net calorific value is of interest. The unit is calories per gram, which may be converted to the alternate units (1.0 kcal/kg = 1.8 Btu/lb = 4.187 kJ/kg). 

The enthalpy of formation of Se02(cr) is obtained from the three accepted measurements of the heat of combustion of Se(trigonal) listed in Table V-22 (references to earlier experimental results or selected values in compilations can be found in [62GAT]). Selenium reacts only partly with oxygen in the bomb calorimeter unless mixed with a combustion aid. Benzoic acid was used for this purpose and the heat evolved by the combustion aid was about 50% in the static bomb and about 90% in the rotating bomb experiments. 

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